Impact drill



April 17, 1956 R. E. SNYDER IMPACT DRILL 2 Sheets-Sheet l Filed July 16, 1951 April 17, 1956 Y R. E. sNYDER IMPACT DRILL 2 Sheets-Sheet 2 Filed July 1e, 195i INVENTOR. /oferl E. .Snyder BY `.IMPACi` DRILL Robert E. Snydenlfasadena, Calif. l Applicgaoniuly 16,1951, serial No. 235,936 s Claims.` (cl. 255-3) My invention relates generally to rotary impact drills and jmore particularly tov impact drills of the Ytype in which relative rotation occurs between the drill shank and a body mounted thereon. This relative rotation elects movement of a reciprocable hammer member and causes a'series of impacts to be delivered to a rotating drill bit.

In my Patent No..2,425,0l2, issued August 5, 1947, I f

have'disclosed certain formsof retarder means which create relative rotation of a body member by fluid, engagement of blades or vanes mounted thereon. The retardation is caused by frictional forces acting between the blades and the drilling fluid or mud, and the blades are not designed to engage the walls of the drilled hole. The present application,` broadly considered, discloses a the drilled hole. yA preferred embodiment of my kinventionincludes essentially one` or more wallrollers which roll against the wall ,of the Ihole as the drill stem is rotated. The resistance to rotation of these rollers retards the rotation ofoan fattacheclbody member, land ,actuates Y the desired impacting means. t

The retarder means have additionalimportantfunctions besides that of creating the desired relative rotation. The rollers, if positioned within the vicinity of the drill bit, `will center the drill stem within the hole. They are alsoadapted to override small projections in the hole to produce a smooth and uniform bore. Under some conditions they may be toothed as in standard reamer rollers tomake biting engagement with thewalls ofthe hole Iand enlarge the bore thereof. As can-beunderstood, the wide variety of earth formations encountered in drilling wells requires the use of lmany types of drills and bits in order to secure the best results. Consequently, the aforementioned operational features will be advan- Vtageous under many different conditions, and the proper use ofmy impact drillawill be apparent to those skilled in the art. y

A major object of my inventionis to provide an impact ydrill which may be operated by the use of wall roller means adapted` for rolling contact with the wall of the hole. l

Another object o f my invention is to provide an imp act drill of this type, which tends to center the drill bit -within the hole and to produce a smooth and uniform bore.

= It is also an object of my invention to provide an yimpact drill of this type which may be operated simulitaneously as a wall reamer.

' An additional object of my invention is to provide an fimpact drill wherein the-impact rate isV substantially inl' new type of retarder ,means which makes Va direct and v substantially constant. rolling contact with the walls` of dependent of the volumeand pressure of the circulating .drilling fluid.`

f iStill another vobject of o my invention is to provide retarder means Which are adapted for Substantially uniform rolling contact with the .walls of the drilled hole to produce `a `uniform impacting rate.;` Y l Itis a further object 'of'my invention to provide rsimple `2,742,264 Patented Apr. 17, 1956 and durable retarder means adapted to withstand rough Vmeans in their lowermost position, immediately after one of thecams hasl overridden' the other.

Fig. 2 is a sidel elevation of a modified form of `my device with the cams about to override each otherj Fig. 3 is a viewsimilar to Figfl of` another modificationV of impact drill;` r y i Fig, v4, is across-section taken along the line`4-i4 of Fig. V5 is a cross-section taken along the line 5 5 of Fig. 2;

Fig. 6 is a cross-section taken along the line 6 6 of Fig. 3; and

Fig. 7 is a cross-section takenalong the line.7-7 Yof Fig. 3. 9

t Referring now to the drawings, and particularly to Fig. l thereof,` a simple form of my improved impact drill is shown, in which the numeral 10 indicates generallya rotatable drillshank. A conventional drill 'stem (not shown) is coupled to the drill shank 10 and transmits driving power to rotate a lower drill bit 111 `Preferf ably, the bit 11 is coupled to a collar 12. forrnedfon` the vlower end of the shank 1li yand maybe easily replaced.

. The shank 10 is ofl hollow tubular `constructionand carries Vthe Vdrilling iuid or mud to ports 13 in the bit 11 where the fluid is discharged to pick up the rock chips and other detritus withinfthe drilled hole. The ydrilling lluid thencirculates upwardlyinthe hole through the space around the shank 10. To this extent the operation of the drill is similar to that of a conventional rotary drill, and the associated drilling equipment including the fluid pumps, driving means, and such, need not be .described herein.

Above the shank collar 12 is an impact structure which includes a reciprocable body member or hammer 14 and an anvil 15. The hammer 14 is formed as a-relatively heavy tubular member and is mounted for rotation and reciprocation on the shank 10. The anvil 15 is formed as an annular ring welded or otherwise fastened tothe upper face-of the collar 12 for rotation with the shank 10. The` engaging faces of the body member )Anand anvil 15 provide cam operating means to cause reciprocation of the body member relative to the shank 10. An vupper cam`17 is shaped on the `body member 14 and a complemental lower cam 18 is formed on the anvil 15. Upon rotationrelative to each other, camsV 17 and 18 cooperate to periodically lift the body 14 Vwhich in turnV v falls to impact on the anvil 15. vA collar 15 is secured to the shank 10 above the body member 1d at such a position as to limit relative4 axial movement ofthe latter while allowing free cooperative movement between cams 17 and`18. v

Near'the top of thebody member 14 are retarder 0r wall roller means 20 surrounding the shank 10. Y VThe roller means 20 are in frictional contactY with the wall of the drilled holeand retard the body member 14 to create relative rotation with respect to the shank 10. The roller means 20 may be formed as a plurality of cylindrical rollers 21 rotatablyl supported by extended axles 22. The

rollers 21 are spaced about the periphery of the shank 10 to rotate on'the individual axles 22 as they revolve about the aXis of the shank. In this form of the drill, the

. a smooth and uniform bore.

'Topositiori the rollers (21 a housing is formed with an upper support Vor ange -24 -and `lower flange 25 lspaced apart and secured to the body member 14. Suitable webs or ribs 26 ,connect the flange 2.4 withthe iiange 25, and ata'p'ered shoulder 27 joins the lower ilange to the 'body member 14. The roller axles 22 are disposed parallel to ,thel axis Vof the shank 1li with the ends rotatably seated in the flanges V24 and 25. As is best seen in'Fvig.v 4, the rollers 21 arejspaced about theperiphery of the shank 10 and have vsuicient clearance with the exterior surface of the 'shank "so that they d'o not'bind'or jam thereon. The outer edges `of the rollers'21 are concentric vwith the `shank 10 and lie on a circle of jdiameter approximately equal to that of the bit 1 0 so as to contact the'wall of the drilled hole and center the'shank therein.

Considering the operation ofV the drill,`it will be 'seen Y thatas the shank Y commences-toprotate, the body 14 is seated upon Ythe anvil through the faces of 'cams 17 and 18. EBecause of the frictional engagement oi cams 17 and 18,:the body 14 rotates with the shank 10, and in turnrotatesthe roller supporting anges 24 and 25. The rollers 21 roll about the wall of the drilled hole much in the manner `of a roller bearing in which Vthe wall acts are required to reciprocate with the body member 14, in addition to rollin-garound vthe wall of hole. As thepbody member 14 falls against the anvil 15, the rollers 21 must be dragged downwardly and this may tend to lessen theimpact. By reference to Fig. 2, an

' alternate form of drill is shown in which the retarder the forceof the impacts.y

means are not required to reciprocate with the hammer body. An impact springmeans'is also used to increase A'suitable drill shank30 is rotatably driven within a drilled hole 'by the customary equipment (not shown). On the lower end of the shank30 is a drill bit 31 and collar '32' generally similar to vthe 'bi-t 1:1 and -collar 12 of the previously described Lform. `Above the collar 32 is a retarder or wall roller means 33 and a body member or hammer 34. The roller means 33 is rotatable on the shank 10 and normally bears against the upper face of the collar 32. The hammer 34 is reciprocably mounted on the shank VV30, and impacts downwardly against the 'roller as an outer race. The presence of the uid mud, and the mud coating. on the walls, as well as the internal friction of the rollers, oifers a substantial resistance to rotation pf the assembly.V The body V14 trends to be retarded reltive to theshank 10 and commences to rotate Vat a slower rate. -As the lrollers 21 turn, they override any small irregularities in the wall of the drilled hole, and thus create To increase the teaming etect of the 4rollers 21 they may be formed with toothed e V- surfaces for biting engagement with the wall.

Y jAlth'ough the body 14 is retarded with respect to the shank 10, it is not normally stopped because the retarding -forcesdepend principally upon the rolling friction created. fhus, there is little tendency for the roller 21 to bind or jam within the hole. Prior devices having wall-engaging means were, in general, provided with non-rotatable andV sharply projected contact members which tended to hang up within the drilled hole. As can be appreciated, the uniform rolling contactof the retarder means used herein' greatly reduces the danger of jamming the drill within the well bore.

When the body member 14 commences rotating at a 'slower rate than the shank 10, the upper cam 17 is caused Vto periodically override the lower cam 18. One or more VWhen the driven cam 17 as rotated counterclockwise with respect to the driving cam 18, as viewed in Fig. l, the former is forced upwardly by the cam action to lift the body member 14. The cam lobes then override and the body member 14 falls to impact against the anvil 15.

As was previously mentioned, the body member 14 is m'adexrelativelyrheavy to form a hammer, and the force :of the'impacts thus created are transmitted through the 'anvil V1'5 and-collar 12 to the bit 11. As 'can be understood, the rate of impacting and the character ot' the impacts may be varied to suit diferent drilling conditions. For example, many of the different types of cam means shown in my copending application Serial No. 734,989, filed VMarch l5, 1947 may be used in'the present device.

a departure from the operation of the drill in my aforementioned patent.

In the form of structure just described the rollers 21 means -33 to transmit energy to the bit `31 through 'the collar 32.`

The roller means A33 includes 'a housing formed of a lower annular ring 35 'and upper ring 36 connected by webs or ribs 37. The housing thus 'formed is both rotatably and axially movable on the shank 10 and supports a plurality Y'of rollers -30 spaced about the periphery of 'the 'shank 136. Each roller 38 is supported on an axle 39 rotatably journaledrb'y the rings 35 'and '36 and spaced outwardly lfrom th'e shank n30, to provide clearance between the surfaces of the rollers and the exterior of the shank. The outer-'edges of the rol-1ers 38 `just contact the wall ofthe drilled hole and createretardin'g friction as has previously. been described. in this lform of the drill, the rollers 38lare again preferably made o'f a durable resilient material, such as rubben--and have a smooth surface adapted to kslidably `engage the 'wall' of-thc hole and the drilling fluid therein. Y Y 4At thetop Vof the ring 36 is artapered'shoulder 40 which-joins Van --anv'il 41 of 'reduced diameter. Theupper face of the anvil 41 is formed las a lower yor driven cam 42;which engages with a complemental upper or driving foam 43 formed tonthe hammer body 34. 'Since Vthe hammer 341s v-iixe'd for rotation With the shank 3i), the driving cam 43 normally lcauses rotation of the driven cam 42 through frictional engagement until such timeas the lretarder means 3-3 decreases the rotational speed of the driven cam. As was previously mentioned, the entire retarder means 33 Ais rotatably and axially movable on the 4shank 30. However, l'as-shownin Fig.l 2, the weight of the structure will normally vcause the lowerY housing ring '35 to seat downwardly against the lcollar 32.

The hammer -34 is xed for rotation with the shank 30 Vby means of inwardly projecting longitudinalv key 45 'which is slidably engaged in the groove 46 formed in the shank to permit reciprocation of the hammer. The upper portion of the hammer 34 is connected to a thin-walled shell 47 which is terminated by a cap 4S. Within the shell 47 is a collar 49 'secured to the shank 30 and the shell Vis thus movable relative to the Acollar upon reciprocation of the hammer 34. The collar 49 serves to limit the axial movement vof 'the hammer y34, but is so positioned as to allow free cooperation between the cams 42- and 43.

To change the character of the impacts delivered by the hammer 34, an impact spring means 50 is confined within the shell `47. The -spring means 50 is preferably formed asa strong coil spring havinglone end seated upon the top of the hammer 34 and the other end abutting the collar 49. Upward movement of the hammer-34 thus causes Vcompression uof the `spring 50. Energy is stored in the spring 50 upon compression, 'and is returned to the hammer 34 upon the downward movement of the latter to increase the magnitude of the impact 'delivered to ythe anvil 41.V

The operation of the drill is', in'general, similar to kthat of the form previously described. Upon rotation ofthe shank 30, the wall roller means'33 Iare retarded duetothe frictional rolling contact with the wall of the drilledl hole. The hammer body 34 is xed for rotation with the shank 10, and as the roller means 33 is` retarded,

` relative rotation occurs between jthe engaging cams 42 and *'43. The upper cam 43 rotatesnclockwisewith respect to the cam 42, as shown in Fig. 2, and periodically lifts the hammer 34. The upward movement of the hammer 34 compresses the spring 5t) to store energy therein.

When cam 43 overrides cam'42, the hammer 34 impacts downwardly 'against the anvil `41 under the combined force of the spring land gravity. 1 j y e' It should be particularly noted that in this form .of the drill, the rollers 38 are not forced to reciprocate within the well b ore. The hammer 34 may thus reciprocate with a'much freer action and a higher impactl rate is made practical. y In Fig. 53 lanother modification of my drillis shown which vdiffers from the previously described forms in the arrangement of elementsand the structure of the wall roller means. A shank 60 is adapted to be rotated within a drilled hole, and carries a lower drill bit 61 coupledto a collar 62. Mounted on the shank 60 is an imp-act structure having a retarder or wall roller means 63 spaced above the collar 62, and an intermediate hammer or body member 64'adapted to reciprocate and impact against an anvil 65. v e .f

The wall roller means 6 3 includes a housing formed of a rotatable upper ring orlsupport 66 and a similar lower ring 67 connected by webs or ribs 68. Attached to the ring-67 is a dependent skirt or sleeve 69 which slidably engages the hammer body 64. Grooves 7) are formed in the sleeve 69 to receive keys 71 formed onthe hammer 64 and lockthe` members for rotation together;

' The upper'ring 66 is held against axial fmovement'on the shank- 66 by meansr of a bearing or Vannular ygroove 72 which iits 'overa collar 73 rigidly secured on the shank.

A plurality ofV rollers 75 `are peripherally spaced about the shank 64) 'and extended between'the rings 66 and 6'7. Eachiroller 75 lis supported on an' axle 76 rotatably jour the shank 6@ to provide clearance between'the exterior surface of the shank and-the rollers. The ,outer surface of the rollers 75 just contacts the wall of the drilled hole, and creates retarding friction, as has been previously de scribed. To increase the roaming effect of the rollers 75,

they are formed with toothed or longitudinallyl serrated surfaces 77, as may best be seen iniFig. 6. The toothed surfaces 77 are adapted to make bitingV engagement with v4o naled in the rings 66 and 67 and' spaced outwardly from 6 Y which is subsequently returned whenlthe'hamrner falls, to increase the force of the impact 'p `Upon retardation of :thewall roller means 63V through thejfrictional rolling contact with the wall kof the drilled hole, Vthe hammer 64 is likewiser'etarded because of the engagement of keys 71 and grooves 70. Retardation of the hammer 64 creates relative rotation between upper cam 81 and lower cam 80 and causes the hammer to be lifted. The hammer 64 in turn falls and impacts against the anvil 65 under the combined force of gravity and the spring SZ. The impacts,V are delivered to the bit 61 through Ythecollarl 62 tof'increas'e `the drilling yrate over that of a conventional rotary drill.v

,.Ascanlbe understood, this yform of my drill is similar in many respectsto ythe previously-described forms, ybut has asomewhat different mode of operation. The retarder means do not reciprocate within the well bore, and consequently the hammer body has a freer Aaction making suitable a high impact rate. The provisionof the serrated roller surfaces 77 creates a more positive frictional eugagement with the wall surface, and the retarding elect is increased. Additionally, the wall is reamed to apositive and uniform bore size. For these reasons, this form of Ythe drill maybe advantageous in certain 'types of drilling operations.

`While I havedescribed my invention with relation to particular forms of my drill, it will Vbe apparent that modifications can be made in each ofithe forms, and there may be` combinations of features `other than'those set forth. i

Accordingly, I do not wish to be restricted to the details of construction hereinfdeseribed, except as definedl in' the appended claims.

Iclaim: i u 1. A rotary impact drill forv earth boring which includes: a 'shank adapted to have a bit attached thereon and to'be rotated in an earth bore;- impact means reciprocably mounted on said shank for delivering impacts thereto;

retarder means rotatably mounted on said shank, said `means comprising a` roller housing and a plurality of wall rollers rotatablymounted therein substantially parallel to the axis of said shank, said rollers being positioned hammer body 64 and anvil 65 provide cam operating lto the anvil 65. The spring means 82 is preferably in the form of a strong coil spring conned between the upper end of the hammer 64 and the roller housing ring 67. The spacing between the ring 67 and hammer 64, and the proportions of the spring 82 are such as to permit sufficient axial movement of the hammer for free cooperation between the cams S0 and 81. Upon lifting of the,

hammer 64, the spring 82 is compressed vto store energy,

for rolling frictional engagement with the wall of said A bore to` retard rotation of said retarder meansgand cam means on said shank frictionally urging said retarderv means to rotate with said shank but responsive to relative rotation between said shank and said retarder means to lift said impact means for impacting against said shank.

2. A rotary impact drill for earth boring which in-v mounted therein substantially parallel to I,the axis yof said shank, said rollersbeing positioned for rolling frictional engagement with the wall of said bore lto retard rotation of said retarder means; and cam means on said shank associated with said hammer and said anvil, said cam means frictionally urging said retarder means to rotate with s aid vshank but being responsive to relative rotation between said shank and said retarder `means to liftsaid hammer for impacting against said anvil. i i

3. A rotary impact drill for earth boring which includes: a shank adapted to have a bit attached thereon and to be rotated in an earth bore having drilling uid therein; a tubular impact hammer reciprocably mounted on said shank; an anvil mounted on said shank below said hammer and held against downward movement; a driving cam mounted on said shank and rotatable therewith; a driven cam mounted on said shank and urged to rotate by rotation of said driving cam, one of said cams being connected to said hammer andreciprocable therewith on said shank; and retarder means rotatably f ing and driven cams,

.7 mountednon said `shank .and connected to vsaid driven vcam for rotation therewith, said means .comprising -a .roller housing and a plurality `pfui/all rollers rotatably mounted therein, .saidV rollers having their axesrfof rotation igenerally parallel to :said shankand positioned for rolling frictionalfengagement with -the wall of said bore to dccrease the rotary speed of Asaid housing and said driven afmand vestablish relative rotation between said cams,

thereby causing said reciprocable cam to lift said hammer and produce an Y.impact Y,on said anvil.

4. A. rotary V.impact-drill fof earth boring which includes: a Vshank adapteduto have Va Adrillbit,attached thereto and to be rotatedV in an earthborehaving drilling tluid therein; .a :driving camdixed onfsaidshank .-for rotation therewith;ia'drivenoamkmounted ou said shank andrfrictionally engaged with-said driving cam; `a tubular impact harnmer rotatably -mountedon said shank and connected with said drivenca-m, saidjhammer reciprocating on said shank yupon relative Y.rotation vbetween said driving and driven camsgvan .annular roller housing connected to said the outer edges of said roller being adapted .for constant rolling Vfrictional engagement `with the `wall of said bore todeerease the rotary speed of said housing and said hammer, whereby to create `relative -rotation between said driv- 5.V Arotary impact drillfor earth boring which includes: a'shank adapted yto have agdrill .bit attached thereto and to be rotated inan earth bore havingdrilli-ng uid therein; an annular roller housing rotatably mounted on said shank .and held against downward movement; a driven cam joined to said roller housing for `rotation therewith; a driving 4cam recipropably mounted on said shank; a ltubu lar .impact 'hammer .keyed to ysaid vshank Vfor reciprocation thereon, said hammer being joined to said driving cam to cause said cam to 7rotate with said shank, said hammer havin-g an-upper extension spaced outwardly .from said shank; impact spring ymeans continedwithin said hammer extension and having'one end abutting -said hammer; a

' collar'within said extension fixed to said shank, -said col- 4lar end abutting'the-other end of said spring means; yand a plurality 'of generally cylindrical rollers rotatably mountedin .said -housingand spaced outwardly from said shank, the outer edges of said rollers being adapted for e constant rollin-g -fr'ietional engagement with the wall of vsaid to and to b e rotated fin 4an earth bore having drilling .duid i therein; a (driving, camvfxed Von said shank `for rotation therewith; 1a driven cam mounted on 'said shank and frictionally engaged with said l.driving cam; a tubular limpact hammer-rotatably mounted on said shank Yand connected 'to said drivenxarn, said hammer reciprocating Yon said reciprocation .thereoha collar xed to saidshank, and .rotatably engaging said housing to hold said housing against axial movement; impact spring means -codntined within saidhousing `extension with one end `abutting said hammer and the other end abutting said housing; and Ya plurality of cylindrical rollers rotatably mounted in said housing andgspaced outwardly from said shank, the surfaces of said rollers being longitudinally .serrated and positioned for frictionalengagement with the wall of said bore to decrease the rotary speed of `said housing and ksaid hammer, whereby to create relative rotation between said driving and driven earns .and cause reeiprocation of said hammer- T7. A..rotary impact drill for earth boring which includes; a shank adapted 4to have a drill bit attached 4there to; an annular roller housing rotatably mounted on .said shank and held against downward movement, and `.provided with a drivenrcam on its upper end rotatable therewith; a tubular hammer reciprocably Amounted on said shank and rotatable therewith and provided with a driving camon its lower end rotatable therewith, said hammer having an upper extension spaced outwardly 'from said shank; spring means within said hammer extension .and conned between said-hammer and a collar on said shank n urging said hammer downwardly; and a plurality of rollers generally parallel to said shank rotatably mounted in said housing outwardly `of said shank and `adapted for individual rolling frictional engagement with the wall of said bore to decrease the .rotary speed-of said housing, Whereby to cause vrelative rotation between said cams and reciprocation of said hammer. y

, `8. .A rotary impact drillfor earth boring which includes: a shank adapted to have a drill bit attached to its lower end; a' tubular hammer reciprocably mounted on said shank for delivering impacts thereto; cam means mounted on said shank including a driving member rotatable with said shank and a driven member frictionally urged to rotate with said driving memberone of said members beinlg connected to said hammer and reciprocable therewith on said shank; and retarder means mounted on said shank and rotatable with said driven cam mem- 'shank upon relative rot-ation between said driving andA e drivenlcams; anannular roller housing rotatably mounted on said shank, 'said'.housing -having a lower extension spaced outwardly from said-shank .and keyed to-said hamber to thereby be urged to rotate with said shank by the frictional 'engagement between said cam members, said retarder means comprising means mounting a plurality of wall rollers on individual axes substantially parallel to and spaced `'about said shank so that said'rollers will have substantially uniform Vrolling contact with the wall of said housing and said bore of such magnitude as to retard rotation of said retarder means and driven cam upon rotation of said shankto thereby cause relative rotation between said cam members and periodic reciprocation of said -reciprocable cam and said hammer.

References Cited in the le of this patent UNlTED STATES PATENTS 1,701,885 Hardesty Feb. 12, 1929 1,745,351 Bishop a Feb. 4, 1930 1,788,377 Bishop Jau. 13, 1931 1,845,074 Billstrom Feb. 16, 1932 2,425,012 Snyder Aug. 5, 1947 2,542,725 VStewart et al Feb. 20, 1951 2,572,307 Brown et al Oct. 23, 1951 

